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为了研究高压扭转工艺对ZK60镁合金组织及性能的影响,采用有限元法对ZK60镁合金试样高压扭转成形过程进行数值模拟,分析成形过程中等效应力、应变分布及变化趋势。通过压扭设备和专用模具对镁合金试样进行高压扭转实验,采用金相显微镜观察试样的显微组织,利用维氏硬度计测量试样的显微硬度。结果表明:高压扭转能有效细化晶粒,改善材料组织结构;在一定的压力下,随着压扭圈数增加,晶粒得到细化,整体显微硬度有较大的提高;高压扭转后试样的显微硬度沿试样径向呈V型分布,与有限元模拟中试样径向的等效应变分布趋势一致。试样不同区域的等效应力、应变和显微硬度差异较大,边缘处的等效应力、应变最大,显微维氏硬度值最高。
In order to study the effect of high-voltage torsion on the microstructure and properties of ZK60 magnesium alloy, the finite element method was used to simulate the high-pressure torsional forming of ZK60 magnesium alloy and the equivalent stress and strain distribution and the trend of variation were analyzed. The high-pressure torsion test was carried out on the magnesium alloy samples by using the compression-pressing equipment and the special molds. The microstructure of the magnesium alloy specimens was observed by a metallographic microscope and the microhardness of the samples was measured by a Vickers hardness tester. The results show that the high-pressure torsion can effectively refine the grains and improve the microstructure of the material. Under certain pressure, with the increase of the number of compression-laps, the grains are refined and the overall microhardness is greatly improved. After high-pressure torsion The microhardness of the sample is V-shaped along the radial direction of the sample, which is consistent with the trend of the equivalent strain distribution in the radial direction of the sample in the finite element simulation. The equivalent stress, strain and microhardness in different regions of the sample are quite different. The equivalent stress and strain at the edge are the largest, and the micro Vickers hardness is the highest.